Dallas Cowboys OG Nate Livings (knee) will have a second surgery on his right knee in six months, according to sources. His last surgery was in February, and he aggravated his knee during organized team activities in May. Typical recovery time for a knee scope is two to four weeks, putting his Week 1 status in doubt. OG Ronald Leary (back), who is competing with Livings for the starting spot, returned to practice this week. OT Jermey Parnell (hamstring) has missed most of the practices in camp, C Ryan Cook (back) has an achy back and OG Kevin Kowalski (knee) is out two to four weeks with a bruised knee.

Dallas Cowboys C Kevin Kowalski has yet to line up at center during organized team activities (OTAs). He has worked the majority of the reps at right guard, as he tries to work his way back into the mix.